In a previous cut off apparatus in a corrugating machine, various attempts have been made to reduce the rigidity of knife cylinders and to realize a specified pressing force between knives. In FIG. 8, for example, the cut off apparatus includes: an upper knife cylinder 53 to which an upper knife 55 and split gears 8a and 8b are attached; a lower knife cylinder 54 to which a lower knife 56, which cuts a corrugated fiberboard web in cooperation with the upper knife 55, and a lower gear 9 which has a meshing engagement with the split gears 8a and 8b are attached; a main drive motor 51 and an auxiliary drive motor 50 which rotationally drive the knife cylinders 53 and 54; and a controller 52 which controls the drive motors 51 and 50. Clearance is formed between the teeth of the split gears 8a and 8b and the teeth of the lower gear 9, which teeth have a meshing engagement with one another when the upper and lower knives 55 and 56 come into contact with each other. The controller 52 controls at least either one of the drive motors 51 and 50 so that a pressing force is applied between the knives 55 and 56 when these knives come into contact with each other (for example, the following patent document 1).
[Patent document 1] Japanese Patent Application Laid-open No. 2002-284430